Efficient photodegradation of 2-chloro-4-nitrophenol over Fe-doped BiOCl nanosheets with oxygen vacancy

Abstract

Photodegradation of organic pollutants emerged as a promising route for environmental remediation. Due to abundant localized electrons, oxygen vacancies (OVs) over BiOCl could promote the adsorption of organic pollutants and activation of oxygen to produce more reactive oxygen species (ROS) during the photocatalytic reaction. Considering the high oxidation potential (E⁰ = 1.8–2.7 V vs. NHE) of the hydroxyl radicals (˙OH), we introduced Fe dopant in the OV-associated BiOCl system (Fe-BOC) to build Fenton-like catalysts, which converted the H₂O₂ generated in the photoreaction to produce more ˙OH for the photodegradation of 2-chloro-4-nitrophenol. Experimental results revealed that the concentration of H₂O₂ in the undoped BiOCl (BOC) photoreaction system was higher, while much more ˙OH was detected in Fe-BOC, indicating that the Fenton-like reaction occurred for the conversion of H₂O₂ into ˙OH over Fe-BOC. In addition, the better charge separation of Fe-BOC could motivate more surface e⁻ for O₂ activation into ˙O₂⁻. Thus, the more reactive oxygen species (˙OH and ˙O₂⁻) produced over Fe-BOC resulted in 3.1 times higher photocatalytic activity in contrast to that of BOC.